You receive LNK2005 errors when you compile an ATL executable (.exe) project in Visual C++ (184235)


The information in this article applies to:

  • Microsoft Visual C++, 32-bit Enterprise Edition 5.0
  • Microsoft Visual C++, 32-bit Enterprise Edition 6.0
  • Microsoft Visual C++, 32-bit Professional Edition 5.0
  • Microsoft Visual C++, 32-bit Professional Edition 6.0
  • Microsoft Visual C++, 32-bit Learning Edition 6.0
This article was previously published under Q184235

SYMPTOMS

When you compile an Active Template Library (ATL) executable (.exe) project in Developer Studio, the _ATL_MIN_CRT preprocessor symbol allows you to use some standard C library functions without having to link in the C run-time library (CRT) startup code. If _ATL_MIN_CRT is defined when you build an ATL executable with Microsoft Foundation Classes (MFC) support, the linker returns the following linker errors:
nafxcw.lib(afxmem.obj) : error LNK2005: "void * _cdecl operator new(unsigned int)" (??2@YAPAXI@Z) already defined in Stdafx.obj
nafxcw.lib(afxmem.obj) : error LNK2005: "void __cdecl operator delete(void *)" (??3@YAXPAX@Z) already defined in StdAfx.obj

CAUSE

Some C run-time library functions require that you provide the CRT startup code. Because both the C run-time and MFC libraries contain definitions for the new and delete operators, there is a conflict for the linker.

RESOLUTION

Remove the _ATL_MIN_CRT preprocessor definition and rebuild the project. To do this, click Settings on the Project menu. On the C/C++ tab, select the Preprocessor category, and remove the _ATL_MIN_CRT definition.

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

  1. Create an ATL COM AppWizard application. On the File menu, click New, and select ATL COM AppWizard as the project type.
  2. Use the information in the following Microsoft Knowledge Base article to add MFC support to your ATL project:

    173974 HOWTO: Add MFC Support to an ATL Project

  3. Add _ATL_MIN_CRT to your preprocessor definitions using the preprocessor settings described in the RESOLUTION section of this article.
  4. On the Build menu, click Set Active Configuration, and choose the Win32 Release MinSize configuration.
  5. Build the project. You should see both LNK2005 errors in the build output window.

REFERENCES

For additional information, please see the following articles in the Microsoft Knowledge Base:

173974 HOWTO: Add MFC Support to an ATL Project

(c) Microsoft Corporation 1998, All Rights Reserved. Contributions by Mark Hagen, Microsoft Corporation.

Modification Type:MajorLast Reviewed:6/6/2005
Keywords:kbtshoot kberrmsg kbprb KB184235 kbAudDeveloper
©2004 Microsoft Corporation. All rights reserved.